Ben-
The terminology is similar if not the same re: Use & non-conforming buildings, etc. Even when I talk to planners, they sometimes say that a structure is "illegal" vs. "non-conforming".
Here's how I interpret the Fannie guidelines to be applied in a real-life situation:
Let's say someone has a house in a one-unit residential zoned area. And, let's say that it conforms to the min. lot size (in fact, it's site area is equal to the minimum lot size). So, as "was", it is conforming with no issues.
Next, let's say that a second unit is built on the property and the size is 1,000sf.
The zoning allows for a second unit, but with conditions: In addition to the required permits, the following is also required per zoning:
A. Lot size has to be minimum + 30% for a second unit.
B. Owner of record must live in one of the units; this requirement transfers with the property.
C. Size of the accessory unit is limited to 800sf.
Our owner of record does not live on-site. So, there are three issues with our subject vs. the zoning ordinance (other than it is not permitted to begin with):
A1: It is on a lot that doesn't qualify for an accessory unit.
B1: It is non-owner occupied (as it turns out, both units are being rented out).
C1: The size of the accessory unit exceeds what would have been allowed.
So, in this case, the general use is still "residential", but (for lack of a better term at this stage) the "real life" use is of a multi-family property. And, to add insult to injury, even if the owner did reside at one of the units, the additional unit would not have been allowed to be built anyway.
In reading Fannie's guidelines, I would interpret the subject to have an illegal use? The conforming use is for one-unit residential, and the real-life use is multi-family residential.
(This will be my last question, as I think I've beaten this horse into the ground!:new_smile-l: )